Estimation of methane fluxes from bottom sediments of Lake Baikal

Granin, N. G.; Muyakshin, S. I.; Макаров, М. М.; Kucher, K. M.; Aslamov, Ilya; Granina, L. Z.; Mizandrontsev, I. B.

doi:10.1007/s00367-012-0299-6

Cited by 26 publications

(27 citation statements)

References 21 publications

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“…Reports on “plumes” or “hydroacoustic plumes” seen on various hydroacoustic systems date back to the 1980s, sometimes not linking the “plumes” clearly to their bubble origin (Merewether et al ; Paull et al ; Lewis and Marshall ). Studies in the Black Sea (Polikarpov ; Naudts et al ), the Sea of Okhotsk (Obzhirov et al ), Hydrate Ridge (Heeschen et al ), the Barents Sea (Sauter et al , Chand et al ), the Framstrait offshore NW Svalbard (Smith et al ), Lake Baikal (Granin et al ), the Gulf of Mexico (Solomon et al ; Talukder et al ; Weber et al ), and the area offshore Santa Barbara (Hornafius et al ; Leifer and Culling ) underline the usefulness of SBES observations to find active seep sites, map their extent and even get an idea of their temporal variability (Quigley et al ; Greinert et al ). First attempts to quantify gas flow rates from SBES were difficult because of limitations of digital data storage capacity (Hornafius et al ) and computer power for data processing.…”

Section: Introductionmentioning

confidence: 99%

“…First attempts to quantify gas flow rates from SBES were difficult because of limitations of digital data storage capacity (Hornafius et al ) and computer power for data processing. Today, this is not a problem anymore and singlebeam as well as multibeam water column data (Nikolovska et al ; Lorenson et al 2011; Weber et al ) are commonly used to visualize gas release and increasingly more often to quantify gas flow rates and fluxes (Granin et al ; Römer et al ).…”

Section: Introductionmentioning

confidence: 99%

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A new methodology for quantifying bubble flow rates in deep water using splitbeam echosounders: Examples from the Arctic offshore NW‐Svalbard

Veloso

Greinert

Mienert

et al. 2015

Limnology & Ocean Methods

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Quantifying marine methane fluxes of free gas (bubbles) from the seafloor into the water column is of importance for climate related studies, for example, in the Arctic, reliable methodologies are also of interest for studying man-made gas and oil leakage systems at hydrocarbon production sites. Hydroacoustic surveys with singlebeam and nowadays also multibeam systems have been proven to be a successful approach to detect bubble release from the seabed. A number of publications used singlebeam echosounder data to indirectly quantify free gas fluxes via empirical correlations between gas fluxes observed at the seafloor and the hydroacoustic response. Others utilize the hydroacoustic information in an inverse modeling approach to derive bubble fluxes. Here, we present an advanced methodology using data from splitbeam echosounder systems for analyzing gas release water depth (> 100 m). We introduce a new MATLAB-based software for processing and interactively editing data and we present how bubble-size distribution, bubble rising speed and the model used for calculating the backscatter response of single bubbles influence the final gas flow rate calculations. As a result, we highlight the need for further investigations on how large, wobbly bubbles, bubble clouds, and multi-scattering influence target strength. The results emphasize that detailed studies of bubble-size distributions and rising speeds need to be performed in parallel to hydroacoustic surveys to achieve realistic mediated methane flow rate and flux quantifications.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A new methodology for quantifying bubble flow rates in deep water using splitbeam echosounders: Examples from the Arctic offshore NW‐Svalbard

Veloso

Greinert

Mienert

et al. 2015

Limnology & Ocean Methods

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“…The local upwelling of the deep waters, which causes the formation of the round currents and decrease in the ice thickness, may be related to the presence of gas hydrates in the bottom sediments [13,14], which were found in their surface layer by the Mir submersible [15]. Under certain conditions, the gas hydrates could rise and, being destroyed beyond the area of their stability at a depth lower than 380 m, gen erate the upwelling.…”

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confidence: 99%

Field studies and some results of numerical modeling of a ring structure on Baikal ice

et al. 2015

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Geological ring structures of various sizes and ori gins are observed on the Earth's surface. In the past decade, ice ring structures on Lake Baikal were regu larly identified by satellites [1]. On April 4, 2009, these structures emerged in the western end of South Baikal and near the Svyatoi Nos Peninsula in Central Baikal [1][2][3] and were destroyed along with the ice at the end of April. The expedition for studying the ice and hydrophysical measurements in the area of the ring structure in South Baikal was organized on April 7. This work presents the results of the field studies and modeling of the currents and variations in the ice thickness.The MODIS satellite data in the visible range with a spatial resolution of 250 m (www.geol.irk.ru) were used for remote study of the ring structure. During the field studies, the ice thickness was measured and the ice cores were drilled along two sections, which transect the center of the ring structure at 51°40′35″ N, 103°52′15″ E (Fig. 1a). The measurement stations were placed in the center of the structure and 1, 2, 3, and 4 km from it along the sections and 7 and 8 km to the west and to the east, respectively, from the center along the EW section. The ice surface in the center of the structure, at its periphery, and in the area of the dark ring was visually similar. No water was visible on the ice surface, and the ice was made up of vertical crys tals. The ice thickness was 74 cm in the center, decreased to 43 cm at the distance of 2 km from the center, and increased up to more than 70 cm beyond the ring.The temperature and electric conductivity of the water column were registered by a SBE 19 profiler. The water in the center was warmer by 0.5°С and less saline (for 2 mg/kg) relative to the periphery (Fig. 1b). In spite of the higher temperature in the center, the ice thickness was similar to that beyond the structure; i.e., the temperature of the water layer was not the major factor responsible for the decrease in the ice thickness. The deepening of the thermocline in the center of the structure (Fig. 1b) indicated the presence of the ring anticyclonic current.According to the tracer movements, the maximum velocities of the water currents (3-4 cm/s) were observed at a distance of 2-3 km from the center of the Abstract-This work presents the results of complex analysis of the field data and of mathematical modeling of the ice ring structure more than 4 km across, which was identified by the space images of South Baikal in April 2009. The measurements revealed that the ice thickness was 74 cm in the center of the structure, decreased to 43 cm at a distance of 2 km, and increased up to 70 cm and more beyond the ring. The ice water in the central part was warmer by 0.5°C and less saline (for 2 mg/kg) relative to the periphery of the structure. According to the tracer movements, the maximum velocities of the ice currents (3-4 cm/s) were observed at a distance of 2-3 km from the center of the structure with minimum ice thickness. The event was modeled using several mathem...

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“…Если удается проследить за отдельными пу зырьками, акустические методы позволяют прямо определить скорости всплытия, размеры отдель ных пузырьков и оценить поток метана в водную толщу [4,24,29,[32][33][34][35][36]. Количество молей газа F s , переносимого всплывающими пузырьками через горизонтальную поверхность единичной площади в единицу времени, в этом случае будет опреде ляться с помощью выражения: где V m -молярный объем метана при температуре и давлении на данном горизонте; S -площадь озву ченной зоны на данном горизонте; N -число пу зырьков, пересекающих за время наблюдения t данную поверхность;  i -объем i го пузырька [4] или Здесь V b (r) -объем пузырька с радиусом r (без учета его несферичности);  -оператор усредне ния; P(h) -давление на глубине h; N b -число обна руженных пузырьков; tдлительность измере ний; R -газовая постоянная; T -температура, °К [26].…”

Section: акустические методы оценки потока метанаunclassified

“…Исключая N 0 из выражений (1) и (2) можно лег ко получить следующую зависимость между пото ком и сечением обратного рассеяния [26,36,37]:…”

Section: акустические методы оценки потока метанаunclassified

Новый Акустический Метод Количественной Оценки Пузырькового Потока Метана В Системе Донные Отложения – Водная Толща И Его Реализация На Примере Моря Лаптевых, Северный Ледовитый Океан

Вячеславович¹,

Yusupov²,

Сергеевич³

et al. 2019

IZVESTIYA

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Актуальность исследования обусловлена необходимостью разработки научно-обоснованного подхода к количественной оценке пузырькового переноса метана (СН4) и других газов на основе акустических методов, позволяющих проводить достоверную оценку потока метана из областей его пузырьковой разгрузки с помощью эхолотов и гидролокаторов. Цель исследования: разработка репрезентативного акустического метода количественной оценки потока метана из областей пузырьковой разгрузки в системе донные осадки – водная толща, основанного на определении количества всплывающих пузырьков, по данным о сечении их обратного рассеяния; обоснование репрезентативности разработанного метода путем сравнения с методом, основанным на проведении специальной калибровки научного эхолота по искусственному газовому факелу. Объекты: газовые факелы – эманации газа в виде всплывающих со дна пузырьков, которые образуют в водной толще устойчивые области их повышенной концентрации. Методы: разработанные авторским коллективом методы оценки потока СН4 из областей пузырьковой разгрузки, основанные на измерении: 1) сечения рассеяния всплывающих пузырьков; 2) калибровки по искусственному газовому факелу. Результаты. Представлен обзор современных акустических дистанционных методов, применяемых для оценки потоков СН4 в водной толще, связанных с выходящими из дна и всплывающими пузырьками. На примере обширной области пузырьковой разгрузки СН4 на шельфе моря Лаптевых обоснована репрезентативность предложенного нового метода, основанного на расчете по сечению обратного рассеяния всплывающих пузырьков СН4. Показано, что оценки величины пузырькового потока, полученные двумя методами: 1) новым методом, разработанным авторами, и 2) методом калибровки эхолота по искусственному газовому факелу, дают схожие результаты: 0,27±0,06 и 0,33±0,07 ммоль•м–2•с–1, соответственно. Таким образом, на практике для дистанционной и оперативной оценки потоков СН4 с участков его пузырьковой разгрузки можно использовать оба метода, с учетом занижения расчета потока по сечению обратного рассеяния примерно на 20 % относительно реальных значений.

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Estimation of methane fluxes from bottom sediments of Lake Baikal

Cited by 26 publications

References 21 publications

A new methodology for quantifying bubble flow rates in deep water using splitbeam echosounders: Examples from the Arctic offshore NW‐Svalbard

A new methodology for quantifying bubble flow rates in deep water using splitbeam echosounders: Examples from the Arctic offshore NW‐Svalbard

Field studies and some results of numerical modeling of a ring structure on Baikal ice

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